拖动通过SKPhysicsJoints附加的雪碧图的最好方法？

Question

我在移动通过SKPhysicsJoint连接的精灵时遇到问题。我有一个touchesMoved方法，如下所示：

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    CGPoint positionInScene = [touch locationInNode:self];
    CGPoint previousPosition = [touch previousLocationInNode:self];
    CGPoint translation = CGPointMake(positionInScene.x - previousPosition.x, positionInScene.y - previousPosition.y);
    CGPoint newPosition = CGPointMake(_selectedNode.position.x + translation.x, _selectedNode.position.y + translation.y);
    [_selectedNode runAction:[SKAction moveTo:newPosition duration:0]];
}

这是可行的，但如果我将重力设置得非常低，它似乎只能将精灵移动25%，如果我将重力设置为默认值，它几乎不会在y轴上移动它。我很困惑，它可能有很多东西，但我在想也许我只需要设置速度或其他什么，但如果是这样，什么是合适的设置？

Answer 1

这应该可以解决问题，我还建议你在抓取精灵时关闭物理，在释放时再次打开图灵。

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

    UITouch *touch = [touches anyObject];
    CGPoint positionInScene = [touch locationInNode:self];
    CGPoint previousPosition = [touch previousLocationInNode:self];
    CGPoint translation = CGPointMake(positionInScene.x - previousPosition.x, positionInScene.y - previousPosition.y);
    //_selectedNode.physicsBody.dynamic = NO;
    [_selectedNode setPosition:CGPointMake(_selectedNode.position.x + translation.x, _selectedNode.position.y + translation.y)];
}

如果你想再次打开物理

- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    _selectedNode.physicsBody.dynamic = YES;
}